(1) Field of the Invention
This invention relates to flow meters to measure the gas and total liquid mass flow rates of a two phase of multiphase fluid.
(2) Description of Related Art
Hydrocarbon fluids produced from wells consist of a mixture of gaseous hydrocarbons, liquid hydrocarbons and water. It is desirable to meter these hydrocarbon fuels in their so-called two-phase state where the term two phase is taken to mean that the fluid consists of both a gas phase and a liquid phase. The liquid phase can be made up of two or more constituents, typically oil and water. Where the volume of gas is high with respect to the volume of liquid the multiphase well fluid is often referred to as wet gas.
Methods and apparatuses for measuring multiphase flow are known. For example WO 99/56091 discloses a method of measuring a gas mass fraction in a mass of liquid and gas flowing along a pipeline. The method includes providing a flow conditioner to create a uniform mixture of gas and liquid and a venturi positioned downstream from the flow conditioner. By measuring differential pressures at points across and/or between the two flow elements the gas mass fraction of the liquid and gas flow may be determined.